The Premyslid king Otakar II (Přemysl Otakar II), who reigned in the years 1253–1278, earned the nickname of “the King of Gold and Iron” due to his military power and wealth. He came to the throne during a favourable foreign-political situation and enjoyed the position of the strongest sovereign in the Empire. In order to receive the inheritance of the Babenbergs, who owned Austria and Styria, he married Margarethe von Babenberg, who was ten years older than him. In the first phase of his reign, he ruled in agreement with the nobility, which profited from the territorial expansion of the Bohemian kingdom.
In 1255 on a crusade to Prussia, he founded the city of Královec (Königsberg), which is Kaliningrad today. Five years later, he defeated the Hungarian king Béla IV near Kressenbrunn and he managed to hold on to Styria, which was the cause of the war. A dispute between the king and nobility on status within the kingdom culminated in a revolt by the nobles.
After its suppression, mutual relations remained tense. Přemysl Otakar II met his death on a Moravian battlefield in 1278 in a war with his rival, the Roman king Rudolph Hapsburg.
His son Wenceslas II (1278–1305) was still a child at the time his father died. A dispute broke out among relatives over who would be the young Wenceslas’ guardian in a rich kingdom. For five years, the country was occupied by Brandenberg forces, and there was a threat that the state would break up. The nobility, however, came together and paid out money for the prince royal Wenceslas to be released from Brandenberg captivity.
They then demanded a greater share of power for this. One of the nobles – Záviš of Falckenstein – married Kunigunde, Přemysl Otakar’s widow. He held the important position of regent, but this was followed by his downfall. Opponents managed to get him arrested, and Záviš was executed in front of Hluboká castle.
At the end of the 13th century, a “confluence” of people occurred at Kutná Hora, when rich deposits of silver ore were discovered. The number of inhabitants of the city rose sharply. With the aid of Italian experts, Wenceslas II put a new coin into circulation – the “Prague Penny.” The penny was minted at the mint in Kutná Hora until 1547. To support the development of mining, Wenceslas II issued a Mining Code (Ius regale montanorum) in 1300. The wealth of the Kutná Hora mines enabled Wenceslas to extend the kingdom to include Chebsko and territory north of the Ore Mountains.
He also obtained the Polish crown and his son Wenceslas tried to take over the vacated the Hungarian throne. However, the Premyslids failed to attain the succession following the extinct Arpad family line.
Wenceslas III came to the throne after the death of his father in 1305. A year later he was murdered in Olomouc when he was preparing to go to Poland to protect the Polish crown. His death concluded over four hundred years of government by the Premyslid family on the Bohemian throne.